Funds are requested to support the Rochester Toxicology Training Program. The overall objective of this program is to provide pre- and postdoctoral training for the next generation of talented, independent toxicologists, who will conduct novel research, and actively transform these finding into new information that will be used by scientists, public health and medical professionals, governmental and other agencies, and the public to improve overall human health and well-being. This program is distinguished by the success of prior trainees, remarkable collegiality and extensive collaborations among faculty and trainees, a broad base of research support, and strong leadership and institutional commitment. The program is dedicated to meeting diverse needs for trainees from many backgrounds, and supporting trainees who seek careers in academia, government and industry. The program?s framework is based on the belief that training requires: (1) multidisciplinary and interdisciplinary approaches; (2) a close relationship between trainee and mentoring team; (3) a culture that supports career development, trainee autonomy, and diversity. The program takes advantage of the range of specialties and resources available at a major academic medical center by reaching beyond the immediate confines of a single department. While housed within the Department of Environmental Medicine, the 33 faculty mentors come from 12 different basic science and clinical departments within the School of Medicine and Dentistry at the University of Rochester. Faculty research spans the entire spectrum of toxicology, from molecular mechanisms and cellular processes to whole animals and human populations. There are 5 major focus areas (neurotoxicology, cardiovascular/pulmonary toxicology, developmental/reproductive toxicology, immunotoxicology, musculoskeletal toxicology), which cut across four contemporary themes: Molecular Modifiers of Toxicity, Developmental Basis of Disease, Epigenetic Regulatory Systems, and Environmental Effects on Stem Cells. During the current cycle of this training grant, new mentoring programs for trainees and faculty have been developed, refinements to the didactic curriculum were adopted, and new strategies to recruit and retain trainees from diverse backgrounds were implemented, including a peer mentoring program. The program is also tightly integrated with other graduate and postdoctoral programs and research support centers at Rochester. Thus, all trainees have access to new institution-wide programs in career development, grant writing, critical thinking and more.